Fuel injection system



Jan. 30, 1951 H. G. sPlER FUEL INJECTION sYs'rEu 3 Sheets-Sheet 1 Filed Oct. 10, 1945 HANS G. SP ER lNvENroR.

ATTORNEY.

TIME

Jarl- 30, 1951 H. G. sPlER 2,539,798

FUEL INJECTION SYSTEM Filed Oct. 10. 1945 3 Sheets-Sheet 2 Il' 'g. lZ.

HANS.4 G. SPIER INVENTOR.

Jan. 30, 1951 H. G. sPlER FUEL INJEcTroN SYSTEM 3 Sheets-Sheet I5 Filed Oct. 10, 1945 AT TOF/Vf. Y.

Patented Jan. 30, 1951 FUEL INJECTION SYSTEM Hans G. Spier, Hamilton, Ohio, assignor to American Bosch Corporation, corporation ol New York Springfield, Mass., a

Application October 10, 1945, Serial No. 621,463

3 Claims. l

This invention relates to fuel injection systems for internal combustion engines and has particular reference to such a system which is completely pressure operated and has no mechanical connection with the engine pistons.

An object of the invention is to provide a new and improved fuel injection system for internal combustion engines which ls completely pressure operated and has no mechanical connection with the engine pistons.

Another object of the invention is to provide a new and improved fuel injection system for use with free piston engines.

Another object of the invention is to provide a new and improved fuel pump for fuel injection systems for free piston engines which is operated by the direct bounce pressure for pumping fuel.

Another object'of the invention is to provide a new and improved injection timer for a fuel injection system.

Another object of the invention is to provide a new and improved-injection timing system for a fuel injection system, which system is operated by delayed pressure rise.

Another object of the invention is to provide a new and improved injection timing system for a fuel injection system which is operated by pressure.

Another object of the invention is to provide a new and improved injection timing system for a fuel injection system, which timing system is operated by cylinder pressure. f

Another object of the invention is to provide a new and improved injection timing system for a fuel injection system, which timing system is operated by pressure from the reverse bounce cylinder.

Another object of the invention is to provide a new and improved adjusting means for a pressure operated injection timing system of a fuel injection system.

Other objects and advantages of the invention will be apparent from the following description taken in connection with the accompanying drawings. It will be understood that many changes may be made in the details of construction and arrangement of parts without departing from the spirit of the invention as expressed in the accompanying claims. I, therefore, do not wish to be limited to the exact details of construction and arrangement of parts s hown and described as the preferred form has been given by way of illustration only.

Referring to the drawings:

(Cl. 12S-139) Fig. 1 is a sectional view of a fuel injection system embodying the invention;

Fig. 2 is a sectional view of a fuel pump for use therewith;

Fig. 3 is a fragmentary view of Fig. 1 on an enlarged scale;

Fig. 4 is a diagram illustrating theoperation of the injection timing system;

Fig. 5 is a diagrammatic view of a fuel injection system embodying the invention and includes a view taken on line 5 5 of Fig. 6 looking in the direction of the arrows;

Fig. 6 is a fragmentary side view of the combustion chamber shown in Fig. 5; and

Fig. 7 is a sectional view taken on line 1-1 of Fig. 6 looking in the direction of the arrows.

Referring more particularly to the drawings wherein similar reference characters designate corresponding parts throughout the several views, the device shown embodying the invention comprises three elements, namely the accumulator nozzle and trip mechanism I, the injection timer 2 and the fuel pump 3.

The accumulator nozzle and trip member I is positioned in alignment with an opening in the wall -l of the engine cylinder and is secured to said wall and is adapted to inject fuel into the combustion chamber of the engine. The said member I is connected to the fuel pump 3 by a pipeline Ia which pipeline is connected to the coupling 5 on the fuel pump 3 at one end and to the coupling 6 on the member I at its other end to provide a fuel pressure supply to the member I. The direct bounce chamber is connected to fuel pump 3 by pipe line 3a.

The member I is also provided with the coupling 1 to which a drain pipe 1a is adapted to be connected for draining oiany leakage or excess fuel in the member I.

The member vI is connected to the injection timer 2 by the pipeline 8.

The said member I includes the tip 9 which extends through and is secured to the wall of the cylinder 4, and also includes the accumulator body portion III and the piston valve portion Il with said members having Van aligned opening closed by the closing plug I2. y

The member 9, accumulator body portion I0 and piston valve portion II are positioned in alignment and are retained in said alignment by the threaded nut I4, the threaded portion of which engages a threaded portion of the clamping sleeve I3 adjacent the upper end of said clamping sleeve I3, said nut I4 engages the annular washer I5 between the lower end of the 3 nut I4 and the outer surface of the flange on the piston valve portion II and when the nut I4 is tightened, the parts are retained in aligned operative relation. The dowel o'r locking pin I 5a is provided in order .to insure` proper alignment between the parts. l

Surrounding the clamping sleeve I3 is provided the jacket I6 which has its upper end. I1 secured to the clamping sleeve I3 by brazing or other suitable means and surrounding the said jacket I6 is positioned the bushing .I8 having the flange l!!V adapted to engage the clamping ring 20. Be-

tween the flange 2i and the flange 22 on the clamping sleeve I3 are positioned the hold-down springs 22a.

Between the clamping sleeve I3 and the jacket j I6 is a cooling space or chamber 23 adapted to receive water or other cooling agent through a line not shown which may be connected to the coupling 24 and said cooling agent may be exhausted through a pipeline connected to the coupling 25 to allow the passage of a stream of such cooling agent to pass into said chamber 23 through the coupling 24 and to be exhausted therefrom through the coupling 25 whereby the nozzle may be cooled by the continuously passing therearound of a continuous stream of said cooling agent.

Surrounding the nozzle tip 9 is positioned the cooling sleeve 26 which allows said cooling agent to surround said nozzle tip 9 between said sleeve 26 and the nozzle tip.

Between the cooling sleeve 26 and the bushing I8 and alsobetween the jacket I 6 and the bushing I8 is the space 21 to allow the draining of any superfluous fuel which may be exhausted through the opening 28 at the upper end of the bushing I8. f

Within the nozzle tip 9 is the needle valve 29 which has an extension 30 extending into the accumulator chamber 3| with said extension 30 having a flange 32 on which is positioned the washer 33 supporting an end of the coil spring 34, the opposite end of which rests against the washer 35.

Within the piston valve portion II is positioned f the piston or flash valve 36 having the enlarged end portion 31 against which rests the washer 38 against which is positioned the coil spring 39 which surrounds said piston or flash valve 36. The piston 36A, which is actuated by pressure through the line 8, in turn actuates the ash valve 36.

The passageway 40 is provided connecting and communicating between the cylinder for the piston or flash valve 36 and the accumulator chamber 3i through the check valve 4 I.

The piston or flash valve 36 has the reduced portion 42 communicating with the fuel pressure line supply 6 and the passageway '40 when the piston or ash valve 36 is in the position shown to allow fuel from the pressure supply 6 to enter said passageway 4U and through the check valve 4I to the accumulator chamber 3| from which the fuel is consequently injected into the combustion chamber of the engine through the nozzle tip 9.

The upper end of the piston or flash valve 36 has a reduced portion 42 forming a fuel receiving fuel by the passageway 43. When the pressure through the pipeline 8 is strong enough to overcome the action of the coil spring 39, the piston or flash valve 36 is moved downward sufciently to close the fuel inlet passage 6, as stated above, and connects fuel line 40 to drain line 1 through the relief section of valve 36 and releases the pressure of the fuel on top of the needle 30 allowing the needle valve tobe opened by the force of fuel trapped under pressure in the accumu- 1 lator chamber 3i which acts on the under side of piston 30a and lifts the' needle valve from its seat and injects the fuel into the engine cylinder.v

cylinder and secured thereto and having a needle valve 45 communicating therewith adapted to receive pressure from the cylinder for operation of the injection timer. y

Surrounding the said body portion 44 is th jacket 46, and there is provided a space 41 between the body portion 44 and said jacket 46 whereby a stream of a cooling medium may be introduced through the coupling 48 and exhausted through the coupling 49 for cooling the heated cylinder gas entering said body from the cylinder.

Within the body portion 44 is the adjustable restriction member 50 which has a threaded portion 5I adapted to be adjusted by turning the extension 52 to adjust the restriction member 50 within the body portion and thereby adjust the delayed pressure rise of the injection timing arrangement as hereinafter described.

The fuel pump 3, as shown in Fig. 2, comprises the body portion 54 having the opening 53 in its lower end adapted to be connected by a line 53a to the combustion chamber or to the direct bounce compression chamber of the engine outside of supply tank and the fuel passes throughout the chamber adapted to be aligned with the fuel in- :on :s is connected to the drain 1 for superfluous 75 inlet check valve 55 to the metering and pumping cylinder 56 which is closed by the closing plug 51 and then to be pumped by the pumping plunger 58 through the delivery valve 59 through the coupling 5 to a pipeline 5a connected with the coupling 6 of the accumulator nozzle and trip mech mism as previously described.

Within the pump body 54 are the piston rings 60 adapted to be actuated by the cylinder pressurel to cause movement of the pumping plunger of said coil spring 6I after the cylinder pressure is reduced. The volume thus pumped may be controlled by a means of restricting the supply ow to the check valve 55 such as the valve 64,

that pressure in the pressure chamber 62 of the injection timer 2 will be rising rapidly when pressure in the cylinder is high and that the amount of delay will be controlled by the size of the leakage allowed by the restriction 50 and the volume of the pressure chamber 62.

In the diagram shown in Fig. 4, line A represents the rise and fall of pressure in the cylinder and dotted line `B represents the rise and fall of pressure in the pressure chamber of the injection timer, D is the point where line A crosses the highest point of line B and C and E are the points where line A crosses line B at the lowest point of line B. A study of this diagram will show how the pressure rise in the pressure chamber is delayed by the triggering mechanism. This pressure rise in the pressure chamber may be adjusted through adjustment of the restrictionil by turning the adjusting screw 52 as previously described. By means of this adjustment the rise of pressure in the pressure chamber may be speeded up or slowed down to alter the relation between the pressure rise in the cylinder and the pressure rise in the pressure chamber and thereby increase or decrease the time lag between the cylinder pressure rise and the operation of the injection apparatus.

.A further means of controlling the timing consists of varying the pressure of spring 39 thereby changing the point on the pressure rise curve (Fig. 4) at which the pressure is suiilcient to move the flash valve 36 into the lower position.

It is pointed out that the injection timer can also be connected to any other cylinder of the A:engine Ywhich .has the .desired pressure char- :acteristic to e'ifect the injection timing functions as, for instance, a reverse bounce cylinder on a free piston engine which cylinder is a cylinder acting to force the pistons in the same direction as does the power cylinder, that is, it is the cylinder opposing the action of the direct bounce cylinder which, in turn, opposes the action of the power cylinder.

The direct bounce cylinder or chamber of a free piston engine is that portion of the cylinders 45 pressure and thereby the whole apparatus is pressure operated and requires no mechanical connection with the engine pistons thereby lending itself particularly for use with free piston engines although its use is not restricted to such engines.

It is pointed out that the transmission of the gas pressure Wave from the timer body 2 to the flash valve can also be made hydraulically or mechanically if desired.

From the foregoing it will be seen that I have provided simple, eicient and economical means for obtaining all of the objects and advantages of the invention.

Having` described my invention, I claim:

' 1. In a device of the character described, a nozzle, a fuel pump for supplying fuel to said nozzle, a pressure operated injection timing means for timing injections by said nozzle, and a restriction between the source of pressure and said injection timing means for causing a substantial delay in the pressure rise at said timing means.

2. In a devicel of the character described, a nozzle, a pressure operated fuel pump for supplying fuel to said nozzle, a pressure operated timing means including a pressure chamber, and a restriction between the source of pressure and said chamber whereby a substantial delay will be caused in the pressure rise at said timing means.

3. In a device of the character described, a nozzle, a pressure operated fuel pump for supplying fuel to said nozzle, a pressure operated timing-means, a passageway connecting said timing means with the direct bounce chamber of an internal combustion device and a restriction in said passageway for causing a substantial delay in the pressure rise in said timing means.

HANS G. SPIER.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,376,277 Higgins, Jr Apr. 26, 1921 1,850,250 Von Salis Mar. 22, 1932 1,856,852 Palisca May 3, 1932 2,246,701 Steiner June 24, 1941 2,420,431 Kalitinsky May 13, 1947 OTHER REFERENCES Ser. No. 348,726, Hurst (A. P.

CJ, published May 11, 1943. 

